Suspensory system for demountable letters and method of forming three-dimensional letters



Oct. 6, 1970 B. H. ADLER 3,531,884

SUSPENSORY SYSTEM FOR DEMOUNTABLE LETTERS AND METHOD OF FORMING THREE-DIMENSIONAL LETTERS Filed June 24, 1968 2 Sheets-Sheet 1 I M/I/EA/TO/Z BEA/JA M/N H A DLER MAHONEY 8c HORNBAKER A 77'0RNE Y5 ADLER 3,531,884 OUNTABLE LETTERS AND METHOD DIMENSIONAL LETTERS 2 Sheets-Sheet 2 B. ENSORY SYSTEM FOR OF FORMING THREE- Filed June 24, 1968 Oct. 6, 1970 SUSP //v VEA/TOR BETA/JAM/A/ ABLE/8 MAHONEY & HORNBAKEE A77'0EA/EY5 atent 3,531,334 Patented Oct. 6, 1970 3,531,884 SUSPENSORY SYSTEM FOR DEMOUNTABLE LETTERS AND METHOD OF FORMING THREE-DIMENSION AL LETTERS Benjamin H. Adler, Beverly Hills, Calif assignor to Republic Corporation, Beverly Hills, Calif., a corporation of California Filed June 24, 1968, Ser. No. 739,289 Int. Cl. G09f 7/02 US. Cl. 40-140 9 Claims ABSTRACT OF THE DISCLOSURE A series of spaced, parallel suspensory members having upwardly and downwardly projecting flanges are mounted on a backing surface appropriately spaced and with the flanges appropriately formed for the selective insertion and removal of letter plates. Intermediate portions of the suspensory members are formed with forwardly opening recesses extending continuously therealong, the recessed surfaces thereof having continuous locating grooves for conveniently locating fastener holes and the completely recessed reception of fasteners through the suspensory members and into a backing surface. The letter plates are transparent with the letters painted thereon, each letter having threedimensional illusory light and solid dark portions with continuous, spaced, solid dark borders enclosing continuous light borders. All of the light portions and continuous light borders are reversely, upwardly angularly lined throughout.

BACKGROUND OF THE INVENTION This invention relates to a suspensory system for demountable letters of the type wherein a series of spaced, parallel and flanged suspensory members receive border portions of letter plates engaged therewith, said suspensory members and letter plates being appropriately formed for selective engagement and disengagement of the letter members. More particularly, this invention relates to a suspensory system of the foregoing type wherein the suspensory members have particularly formed recesses extending along the lengths thereof having unique locating means for conveniently locating fastener holes and fasteners totally recessed therein and extending through the suspensory members for securing the same to a backing surface. Still further, the suspensory system letter plates of the present invention involve uniquely formed, three-dimensional illusory letters painted thereon giving a much more positive three dimensional effect than has heretofore been possible with similar letter plates of prior suspensory systems.

Various prior forms of suspensory systems for demountable letters have heretofore been provided, certain of which have been of the general type hereinbefore described, but without the unique features of the present invention. For instance, in the use of suspensory systems of the type herein involved, it has been the usual practise to form the suspensory members at the factory in a series of uniform lengths, each having a series of uniformly spaced fastener holes. Thus, when it is desired to construct a demountable letter sign or display, the appropriate lengths of suspensory members are chosen, said suspensory member lengths taken to the construction site, and then the suspensory member lengths properly cut to size to suit the particular sign or display to be constructed.

One of the major difiiculties with these prior forms of suspensory members is that at the time of the factory forming of the fastener holes in said suspensory members, it is never known eXactly what length will be required at the construction site for the particular sign or display. As a result, on many occasions when the suspensory members are cut to proper size at the construction site, great care must be taken to avoid cutting the suspensory members directly through one of the preformed and preplaced fastener holes. Obviously, if a cut through one of the suspensory members passes through a fastener hole, the finally constructed sign or display will be unsightly and, therefore, undesirable.

Another difliculty with the prior constructions is that with such prior constructions, once the fasteners are installed through the fastener holes thereof for securing the same to a backing surface, such fasteners having headed portions thereon, necessarily project forwardly from the suspensory members. Not only does this forward fastener projection lend a certain amount of unsightliness to the final construction, but also, such forward projection interferes with the insertion into and removal of the letter plates therefrom during use. Th insertion and removal of the letter plates requires certain manipulation thereof and there is always the danger, due to such fastener interference, of damaging the letter plates and making them unsuitable for further use.

A still further factor involved with suspensory systems of the immediate type concerns the particular formation of the letters on the letter plates. These letter plates are normally formed of a transparent plastic and have the letters painted on back surfaces thereof of a contrasting coloration to the coloration of the backing surface upon which the suspensory members are mounted. In this manner, the painted letters are readily distinguishable through the transparent letter plates and against the contrasting backing surface.

In order to make the letter plates more attractive and the letters thereof more easily distinguishable, various prior attempts have been made to paint the letters thereon in a form attempting to give a three-dimensional illusory effect. None of these prior attempts, however, have been completely satisfactory and particularly when the final sign or display construction is viewed from a distance which is normally the case. To the contrary, in many instances, the attempts to give the three-dimenisonal illusory efi'ect have made the letters on the letter plates less distinguishable and more diflicult to discern the particular letter being depicted.

Objects and summary of the invention It is, therefore, an object of this invention to provide a suspensory system for demountable letters of the type including a series of spaced, parallel suspensory members appropriately positioned and having appropriate flanges formed thereon for the selective insertion and removal of letter plates wherein the suspensory members are secured by fasteners to a backing surface, yet the fasteners providing such securement are completely recessed and free of any possible interference with the letter plates during the required manipulation thereof for such insertion and removal. The suspensory members, in many respects, are of the usual type formed with appropriate flanges for the selective engagement with and secure mounting of the usual flat, rectangular letter plates but, according to the present invention, such suspensory members are formed at intermediate front surfaces thereof with lengthwise recesses. During the installation of the suspensory members on a backing surface for the construction of a particular sign or display, the fasteners required for securing the suspensory members to the backing surface are installed within said suspensory member recesses and projecting through the suspensory members into the backing surface so that any projecting portions of said fasteners are recessed totally within the suspensory member recesses and free of any possible interference with the letter plates during engagement of the letter plates with the suspensory members.

It is a further object of this invention to provide a suspensory system for demountable letters of the foregoing general character and particularly with the suspensory members having the above described fastener recesses thereon wherein special fastener locationing means is provided in said recesses, eliminating the necessity of performing any fastener holes through the suspensory mem bers at the factory, but rather permitting the formation of such fastener holes at the construction site and in the exact locations required for the particular sign or display being constructed. In other words, rather than the prior practice of forming the suspensory members at the factory with a series of fastener holes therein which must be avoided at the construction site during the cutting of the elongated suspensory members to proper length for the particular sign or display as hereinbefore discussed, the suspensory members may be manufactured of standard lengths at the factory and completely free of any fastener holes. Such suspensory members are then quickly cut to appropriate length at the construction site and by use of the unique fastener locating means, the fastener holes are quickly formed at proper locations for securely supporting the suspensory members on the backing surface, merely with the use of conventional tools and without any special skill being required.

The preferred form of the fastener locating means in each of the suspensory member recesses is a V-shaped cross section, lengthwise extending groove in the inner surface of each recess providing a perfect guide for the tool forming the fastener holes. Thus, it is merely necessary to engage such tool in the particular recess groove and the fastener holes are always located properly relative to the remainder of the particular suspensory member. Furthermore, where the suspensory members and backing surface are formed of the appropriate materials, it is possible, in certain cases, to merely install the suspensory members without the preforming of any fastener holes, that is, by the mere shooting of conventional pop rivets through said suspensory members and into the backing surface, again making use of the unique locating groove to quickly and conveniently guide the rivet installing operation.

It is still a further object of this invention to provide a unique form of letter plates for use with suspensory systems of the foregoing general type wherein the letters painted on the surfaces of the letter plates are formed in a new and unique manner giving a much more complete and perfect visual three-dimensional illusory effect than has heretofore been possible even though said letters are merely painted on a two-dimensional plane surface. Each of the letters is formed with the somewhat conventional three-dimensional illusory, adjacent, main solid dark and light portions. In addition, however, spaced, continuous solid dark borders enclosing a continuous light border are formed on each of the letters, and all of the main light portions and light border are reversely, upwardly angularly lined, the borders and lining combining to give an improved three-dimensional illusory effect.

Other objects and advantages of the invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only.

Brief description of the drawing FIG. 1 is a fragmentary, front elevational view illustrating an embodiment of an assembled suspensory system incorporating certain of the principles of the present invention, but without attempting to depict the improved letter formation due to the reduced scale of said view;

FIG. 2 is an enlarged, fragmentary, vertical sectional view looking in the direction of the arrow 22, in FIG. 1;

FIG. 3 is an enlarged, fragmentary, horizontal sec- 4 tional view looking in the direction of the arrows 33 in FIG. 1;

FIG. 4 is an enlarged, fragmentary, vertical sectional view taken from the lower portion of FIG. 2 and illustrating the final assembled engagement of letter members or plates with a suspensory member;

FIG. 5 is a view similar to FIG. 4 but showing letter plates in various positions during assembly engagement with a suspensory member to illustrate the assembly steps for mounting the letter members with the suspensory members;

FIG. 6 is an enlarged, vertical sectional view taken through one of the suspensory members of FIGS. 1 through 5;

FIGS. 7, 8 and 9 are enlarged, front elevational views of various letter plates removed from the suspensory system of FIGS. 1 through 6 illustrating the unique construction and formation of capital letters thereon having the improved three dimensional illusory effect; and

FIG. 10 is an enlarged, fragmentary, front elevational view of a letter plate similar to FIGS. 7, 8 and 9, but depicting a representative lower case letter.

DESCRIPTION OF THE BEST EMBODIMENT CONTEMPLATED Referring to FIGS. 1 through 6 of the drawings, an embodiment of the suspensory system for demountable letters and the like of the present invention as illustrated and includes a series of spaced, elongated and parallel suspensory members, generally indicated at 10, secured in a manner to be hereinafter described to a planar or corrugated background or backing surface 12 of a backing member 14. The suspensory members 10 are spaced on the backing surface 12 and otherwise adapted, again in a manner to be hereinafter described, for demountably suspending a series of letter plates or members, generally indicated at 16 having letters 18 formed thereon. It is initially pointed out that use of the term letter or letters is intended to define any form of usual depiction it might be desirable to provide on the letter plates 16, such as, the usual and variously formed alphabetical letters, various symbols, numerals and the like, so that said term or terms should be construed in this broader sense.

The suspensory members 10 are substantially identical, preferably being extruded from any of the usual transparent plastics, each suspensory member including an elongated intermediate portion 20 terminating downwardly in an elongated lower flange 22 and terminating upwardly in an elongated upper flange 24. The intermediate portion 20 has a unique continuous recess 26 formed in a forward surface thereof, at the moment ignoring the particular unique formation thereof, for receiving fasteners 28 therein extending rearwardly through said intermediate portion and into the backing surface 12 of the backing member 14 to thereby secure each of said suspensory members 10 rearwardly on the backing surface and with a rearward surface 30 of said intermediate portion abutting said backing surface. The lower flange 22 has a rearward surface 32 spaced forwardly from the backing surface 12 and the upper flange 24 has a rearward surface 34 spaced an equal distance forwardly from said backing surface, with the lower flange projecting downwardly a greater distance than said upper flange projects upwardly for a usual purpose to be hereinafter described, so that said lower and upper flanges form with said intermediate portion 20 and backing surface 12 a downwardly opening, generally U- shaped cross section, lower channel 36 of a greater depth than an upwardly opening, generally U-shaped cross section, upper channel 38.

The letter plates or members 16 are preferably formed from identically vertically sized and rectangularly configured, transparent or substantially transparent plastic blanks having parallel, forward and rearward planar surfaces 40 and 42 that the same may be cut in the usual manner from conventional transparent plastic sheets. The desired letter or letters, generally indicated at 18, are preferably silk screen painted on the rearward surface 42 taking advantage of all of the various techniques of silk screen effects to produce the aesthetic appearance desired such as shading, mock angularity and other, but again, for the moment, ignoring the unique particular construction and formation thereof to produce the improved three-dimensional illusory effect important to certain principles of the present invention. Furthermore, the letter or letters 18 are preferably formed on the letter member 16 spaced inwardly from the border extremities thereof so that there remain transparent border portions 44 surrounding said letter or letters including upper border portions 46 terminating in upper edges 48 and lower border portions 50 terminating in lower edges 52.

The backing member 14, which may actually be a separate member or merely the side wall of a room or building or any other structure, has the backing surface 12 thereof preferably formed of a plain coloration and the letters 18 of the letter member 16 are formed of a contrasting coloration, for instance, a light backing surface with darker letters or the opposite, so that said letters are readily visually discernible against the coloration of the backing surface 12, while said backing surface is visually discernible through the transparent border portions 44 of the letter members around said letters. Thus, the usual aesthetically pleasing effects may be produced by the suspensory system of the type of the present invention and such system is readily modifiable in the many usual manners to produce separate and distinct coloring effects for different installations.

In providing the letter members 16 selectively mountable on the suspensory members 10, the letter member upper and lower edges 48 and 52 are spaced apart a greater distance than the spacing between the lower flange 22 of an upper suspensory member and the upper flange 24 of a lower or underlying suspensory member 10 so that any of the letter members may be positioned within the respective suspensory member lower and upper channels 36 and 38 engaged rearwardly of the suspensory member lower and upper flanges 22 and 24. At the same time, in order to permit insertion and removal of the letter member 16 from the suspensory members 10, the letter member spacing of the upper and lower edges 48 and 52 thereof is a distance less than the distance from the upper extremity of the upper flange 24 on said underlying suspensory member and the upper extremity of the lower flange 22 on said upper suspensory member 10, in other words, the distance between the upper and lower edges 48 and 52 on the letter members 16 is less than the distance between the upper flange eX- tremity on said underlying suspensory member and the lower extremity of the lower flange of said upper suspensory member plus the depth of the lower channel 36 on said upper suspensory member. It is also preferable that the forward spacing of the rearward surfaces 32 and 34 on the suspensory member lower and upper flanges 22 and 24 from the backing surface 12 will be an amount greater than the thicknesses of the upper and lower border portions 46 and 50 of the letter members 16 so that said letter member border portions may be freely slidably received in the suspensory member lower and upper channels without any deformation of the letter members or suspensory member.

In selectively mounting the letter members 16 engaged by the suspensory members 10, therefore, the upper border portion 46 of a letter member is inserted fully upwardly into the lower channel 36 of an upper of the suspensory members 10 as shown at the lower portion of FIG. 5. At the same time, the lower border portion 50 of said letter member 16 remains slightly outwardly until said upper border portion 46 is so fully received, after which, said lower border portion is merely moved rearwardly past the upper extremity of the upper flange 24 on the underlying of the suspensory members 10 in the manner shown at the upper portion of FIG. 5.

When the rearward surface 42 of the particular letter member 16 is finally positioned rearwardly abutting the backing surface 12 on the backing member 14, the letter member may be slid downwardly forwardly engaged in the upper channel 38 on the underlying of the suspensory members 10 and due to the particular dimensioning of the letter member upper and lower border portions 46 and 50, the letter member 16 will still remain forwardly engaged partially within the lower channel 36 of the upper of the suspensory members 10 in the final position shown in FIG. 2. Removal of a letter member 16 is obviously accomplished by just the opposite procedural steps.

More particularly to the specific improvements of the present invention, the intermediate portion 20 of each of the suspensory members 10 is formed with the continuous recess 26 in the forward surface thereof, the same being previously briefly alluded to as receiving the fasteners 28 therein extending rearwardly through said intermediate portion and into the backing surface 12 of the backing member 14. Such recess 26 is preferably generally U-shaped in vertical cross-section as shown in FIGS. 2, 4, 5 and 6, extending lengthwise throughout all of the suspensory members 10. The purpose of the recess 26 is to completely eliminate any forward protrusion of the fasteners 28 from the forward surface of the suspensory members 10 so that the fasteners may be installed within the particular recess and into the backing member 14 fully recessed and out of possible interference with edges of the letter plates 16 during manipulation of said letter plates when inserted or removed from the suspensory members 10.

Furthermore, the inner vertical surface 54 of the recess 26 is formed, preferably vertically midway thereof, with a continuous lengthwise, generally V-shaped cross section, fastener locating groove 56. Locating groove 56 serves to perfectly locate fastener holes 58 formed through the suspensory member intermediate portion 20 within the recess 26, Thus, it is unnecessary to preform the fastener holes 58 at the factory, but rather the suspensory members 10 may be formed of uniform lengths without said holes and transported to the site of construction where the fastener holes may be conveniently drilled, using the fastener locating groove 56, in proper locations to suit the particular sign or display being constructed, thereby eliminating the various difiiculties hereinbefore discussed. Also, in certain instances where the various suspensory member and backing member materials are appropriate, it is possible to shoot pop rivets directly through the suspensory member intermediate portions 20, again making use of the fastener locating groove 56, in which case, any forming of the fastener holes 58 would be eliminated.

It is apparent, therefore, that the suspensory member recess 26 formed in the intermediate portion 20 serves the dual purpose of both eliminating any forward projection of the fasteners 28 by maintaining the exposed portions thereof fully recessed therein, and further providing the convenience of the fastener locating groove 56 for either locating the proper forming of the fastener hole 58 at the site of construction or serving as location for the shooting of pop rivets through the suspensory members at the construction site and without any preforming of the fastener holes. Furthermore, it is pointed out that the attributes of the suspensory member recess 26 with the fastener locating groove 56 are fully applicable regardless of the particular type of fasteners used, whether of the particular type as illustrated by the fasteners 28, pop rivets as described or any other of the various fastener constructions used for such purposes.

Referring particularly to FIGS. 7 through 10, each of the letter plates 16 has one or more letters 18 formed thereon, preferably being silk screen painted on the letter plate rearward surfaces 42 as hereinbefore described, and in view of the transparency of said letter plates, the letters are fully visible therethrough. More important, each of the letters 18 is formed with adjacent main solid dark portions 60 and light portions 62 patterned in the somewhat usual three-dimensional illusory form. According to the present invention, the letters 18 are also each formed with spaced, continuous, solid dark outer and inner borders 64 and 66 enclosing a continuous light border 68 the outer borders 64 being considerably wider than the inner borders 66. Additionally, all of said main light portions 62 and said light border 68 are reversely upwardly angularly lined throughout, that is, said light portions and border have uniformly spaced lines indicated at 70 angling upwardly to the left as viewed which would normally be considered the reverse of the direction of projection of the particular letter 18.

At angular changes of direction of the solid dark portions 60 where such dark portions continue in said changed directions, the parts of said dark portions at the direction changing corner are separated by an accentuating light corner 72 at an angle not necessarily the same as the light portion uniformly spaced lines 70 or even in the same direction in view of line 72 being a corner line. Further, these accentuating light corner lines 72 separating the part of the dark portions 60 are preferably of the same approximate width as the spacing between the light portion uniformly spaced lines 70. Still further, the main light portions 62 are similarly formed with accentuating dark corner lines 74 separating angular parts of the light portions, said accentuating dark corner lines 74, however, being a marked amount greater thickness in certain cases than the light portion uniformly spaced lines 70, although again not necessarily at the same angle or in the same direction in view of it being a corner line.

With the letter plates 16 transparent or substantially transparent, the light portions '62, the accentuating light corner lines 72 and the light borders 68 of the letters 18 are merely unpainted except for the series of uniformly angled or parallel lines 70 and the accentuating dark corner lines 74, said lines '70 and 74 normally being painted the same color as the solid dark portions 60 and the solid dark borders 64 and 66 although they could be contrasting colors. The solid dark portions 60 and the solid dark borders 64 and 66, of course including the angular lines 70 and the accentuating dark corner lines 74, are merely painted a solid color, either opaque or transluscent, so that there is a relatively sharp contrast between the light and dark portions from the visual standpoint. It will also be noted that where the particular letter 18 includes an interior opening such as the letter P of FIG. 7 and the letter A of FIG. 9, the spaced solid dark borders 64 and 66 enclosing the light border 68 are carried around said interior opening, and in all cases where the inner solid dark border 66 directly abuts a solid dark portion 60, the inner solid dark border blends directly into the solid dark portion.

Thus, with the letter plates 16 mounted on the suspensory member and against the plain, light coloration of the backing surface 12, the letter solid dark and light portions 60 and 62 are arranged in the usual manner for producing the usual three-dimensional illusory effect, even though said letters 18 are only formed on a single surface, actually in two-dimension. In addition according to the present invention, however, the sharply accentuating light and dark corner lines 72 and 74 in the main dark and light portions 60 and 62, respectively, with the solid dark borders 64 and 66 in combination with the light border 68 and the parallel angular lines 70 throughout all light portions and light borders, much more clearly and distinctly bring out and define this three-dimensional illusory effect than has ever been produced with prior similar constructions. The spaced solid dark borders 64 and 66 8 with the enclosed light borders 68 give a strong recessed flanged or fiat background effect for all peripheral edges of the letters 18 as well as at any interior openings thereof, while the parallel angular lines 70 in all light portions 62 more clearly define the illusory forwardly protruding angular effect for such light portions, this being true whether the particular of the letters 18 are capital letters as shown in FIGS. 7, 8 and 9 or are lower case letters as shown in FIG. 10. Still further, the accentuating light and dark corner lines 72 and 74 even more clearly define the illusory angular effect of both the dark and light portions 60 and 62, sharply delineating the illusory change in angle of these dark and light portions.

According to the principles of the present invention, therefore, an improved suspensory system for demountable letters is provided wherein the attaching fasteners 28 for the suspensory members 10 are perfectly located through said suspensory members at the site of construction by the fastener locating grooves 56 and the fastener holes 58 may be formed at said construction site to perfectly suit the individual sign or display being constructed. Also, all of the fasteners 28 for the suspensory members 10 are totally recessed within the front surfaces of said suspensory members totally out of any possible interference with the manipulation of the letter plates 16 during the mount ing of the letter plates on the suspensory members. Still further, all of the letters 18 are formed on the letter plates 16 in a new and different manner giving a sharp and distinctive three-dimensional illusory effect far superior to the prior similar constructions.

I claim:

1. In a demountable letter suspensory system of the type having spaced, parallel suspensory members mounted rearwardly against a backing surface, said suspensory members having flanges formed thereon engaging border portions of letter members demountably supporting said letter members adjacent said backing surface; the improvements comprising: a continuous lengthwise recess formed in a forward surface of each of said suspensory members, said recess defining a recess inner surface spaced rearwardly of said forward surface; a continuous lengthwise fastener locating line on said recess inner surface; and a series of fasteners extending through said recess inner surface and said each suspensory member and into said backing surface securing said each suspensory member to said backing surface, said fasteners being fully recessed Within said recess and located in a uniform predetermined relationship to said fastener locating line.

2. A demountable letter suspensory system as defined in claim 1 in which said fastener locating line is formed by a continuous lengthwise fastener locating groove on said recess inner surface; and in which said fasteners extend rearwardly through said fastener locating groove.

3. A demountable letter suspensory system as defined in claim 1 in which a continuous lengthwise fastener locating groove is formed in said recess inner surface, said groove having a generally V-shaped cross section forming said fastener locating line at the apex thereof; and in which said fasteners extend rearwardly through said fastener locating groove.

4. A demountable letter suspensory system as defined in claim 1 in which fastener holes receiving said fasteners therethrough are formed rearwardly through said recess inner surface and said each suspensory member, said holes having center lines substantially coinciding with said fastener locating line.

5. A demountable letter suspensory system as defined in claim 1 in which a continuous lengthwise fastener locating groove is formed in said recess inner surface, said groove being generally V-shaped in cross section and forming said fastener locating line at the apex thereof; and in which fastener holes are formed rearwardly through said recess inner surface and said each suspensory member, said holes having center lines substantially coinciding with said fastener locating line.

6. A demountable letter suspensory system as defined in claim 1 in which said suspensory system letter members are substantially transparent letter plates having letters formed on a surface thereof of a general coloration contrasting to a coloration of said backing surface, said backing surface being discernible through said letter plates at parts of said letter plates free of said letter coloration, said letters having adjacent solid dark and light main portions giving a three-dimensional illusory effect; and in which continuous, spaced, solid dark borders are formed on each of said letters enclosing a continuous light border and outlining said solid dark and light main portions.

7. A demountable letter suspensory system as defined in claim 1 in which said suspensory system letter members are substantially transparent letter plates having letters formed on a surface thereof of a general coloration contrasting to a coloration of said backing surface, said backing surface being discernible through said letter plates at parts of said letter plates free of said letter coloration, said letters having adjacent solid dark and light main portions giving a three-dimensional illusory effect; in which continuous, spaced, solid dark borders are formed on each of said letters enclosing a continuous light border and outlining said solid dark and light main portions; in which at least said letter light main portions are formed with spaced, parallel, angular lines; and in which at least certain of said letter solid dark and light main portions have contrasting light and dark corner lines separating angular parts thereof.

8. A demountable letter suspensory system as defined in claim 1 in which said suspensory system letter members are substantially transparent letter plates having letters formed on a surface thereof of a general coloration contrasting to a coloration of said backing surface, said back ing surface being discernible through said letter plates at parts of said letter plates free of said letter coloration, said letters having adjacent solid dark and light main portions giving a three-dimensional illusory effect; in which continuous, spaced, solid dark borders are formed on each of said letters enclosing a continuous light border and outlining said solid dark and light main portions; and in which at least said letter light main portions are formed substantially throughout with spaced, parallel, reversely upwardly angular lines.

9. A demountable letter suspensory system as defined in claim 1 in which said suspensory system letter members are substantially transparent letter plates having letters formed on a surface thereof of a general coloration contrasting to a coloration of said backing surface, said backing surface being discernible through said letter plates at parts of said letter plates free of said letter coloration, said letters having adjacent solid dark and light main portions giving a three-dimensional illusory effect; in which continuous, spaced, solid dark borders are formed on each of said letters enclosing a continuous light border and outlining said solid dark and light main portions; and in which all of said letter light main portions and light borders are formed substantially throughout with spaced, parallel, reversely upwardly angular lines.

References Cited UNITED STATES PATENTS 3,407,525 10/1968 Connell 40-140 EUGENE R. CAPOZIO, Primary Examiner W. J. CONTRERAS, Assistant Examiner 

